/* Copyright 2016 Mozilla Foundation
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import {
  animationStarted, DEFAULT_SCALE, DEFAULT_SCALE_VALUE, MAX_SCALE,
  MIN_SCALE, noContextMenuHandler, NullL10n
} from './ui_utils';

var PAGE_NUMBER_LOADING_INDICATOR = 'visiblePageIsLoading';
var SCALE_SELECT_CONTAINER_PADDING = 8;
var SCALE_SELECT_PADDING = 22;

/**
 * @typedef {Object} ToolbarOptions
 * @property {HTMLDivElement} container - Container for the secondary toolbar.
 * @property {HTMLSpanElement} numPages - Label that contains number of pages.
 * @property {HTMLInputElement} pageNumber - Control for display and user input
 *   of the current page number.
 * @property {HTMLSpanElement} scaleSelectContainer - Container where scale
 *   controls are placed. The width is adjusted on UI initialization.
 * @property {HTMLSelectElement} scaleSelect - Scale selection control.
 * @property {HTMLOptionElement} customScaleOption - The item used to display
 *   a non-predefined scale.
 * @property {HTMLButtonElement} previous - Button to go to the previous page.
 * @property {HTMLButtonElement} next - Button to go to the next page.
 * @property {HTMLButtonElement} zoomIn - Button to zoom in the pages.
 * @property {HTMLButtonElement} zoomOut - Button to zoom out the pages.
 * @property {HTMLButtonElement} viewFind - Button to open find bar.
 * @property {HTMLButtonElement} openFile - Button to open a new document.
 * @property {HTMLButtonElement} presentationModeButton - Button to switch to
 *   presentation mode.
 * @property {HTMLButtonElement} download - Button to download the document.
 * @property {HTMLAElement} viewBookmark - Element to link current url of
 *   the page view.
 */

/**
 * @class
 */
var Toolbar = (function ToolbarClosure() {
  /**
   * @constructs Toolbar
   * @param {ToolbarOptions} options
   * @param {HTMLDivElement} mainContainer
   * @param {EventBus} eventBus
   * @param {IL10n} l10n - Localization service.
   */
  function Toolbar(options, mainContainer, eventBus, l10n = NullL10n) {
    this.toolbar = options.container;
    this.mainContainer = mainContainer;
    this.eventBus = eventBus;
    this.l10n = l10n;
    this.items = options;

    this._wasLocalized = false;
    this.reset();

    // Bind the event listeners for click and hand tool actions.
    this._bindListeners();
  }

  Toolbar.prototype = {
    setPageNumber(pageNumber, pageLabel) {
      this.pageNumber = pageNumber;
      this.pageLabel = pageLabel;
      this._updateUIState(false);
    },

    setPagesCount(pagesCount, hasPageLabels) {
      this.pagesCount = pagesCount;
      this.hasPageLabels = hasPageLabels;
      this._updateUIState(true);
    },

    setPageScale(pageScaleValue, pageScale) {
      this.pageScaleValue = pageScaleValue;
      this.pageScale = pageScale;
      this._updateUIState(false);
    },

    reset() {
      this.pageNumber = 0;
      this.pageLabel = null;
      this.hasPageLabels = false;
      this.pagesCount = 0;
      this.pageScaleValue = DEFAULT_SCALE_VALUE;
      this.pageScale = DEFAULT_SCALE;
      this._updateUIState(true);
    },

    _bindListeners: function Toolbar_bindClickListeners() {
      var eventBus = this.eventBus;
      var self = this;
      var items = this.items;

      items.previous.addEventListener('click', function() {
        eventBus.dispatch('previouspage');
      });

      items.next.addEventListener('click', function() {
        eventBus.dispatch('nextpage');
      });

      items.zoomIn.addEventListener('click', function() {
        eventBus.dispatch('zoomin');
      });

      items.zoomOut.addEventListener('click', function() {
        eventBus.dispatch('zoomout');
      });

      items.pageNumber.addEventListener('click', function() {
        this.select();
      });

      items.pageNumber.addEventListener('change', function() {
        eventBus.dispatch('pagenumberchanged', {
          source: self,
          value: this.value,
        });
      });

      items.scaleSelect.addEventListener('change', function() {
        if (this.value === 'custom') {
          return;
        }
        eventBus.dispatch('scalechanged', {
          source: self,
          value: this.value,
        });
      });

      items.presentationModeButton.addEventListener('click',
          function (e) {
        eventBus.dispatch('presentationmode');
      });

      items.openFile.addEventListener('click', function (e) {
        eventBus.dispatch('openfile');
      });

      items.print.addEventListener('click', function (e) {
        eventBus.dispatch('print');
      });

      items.download.addEventListener('click', function (e) {
        eventBus.dispatch('download');
      });

      // Suppress context menus for some controls
      items.scaleSelect.oncontextmenu = noContextMenuHandler;

      eventBus.on('localized', (evt) => {
        this._localized();
      });
    },

    _localized: function Toolbar_localized() {
      this._wasLocalized = true;
      this._adjustScaleWidth();
      this._updateUIState(true);
    },

    _updateUIState: function Toolbar_updateUIState(resetNumPages) {
      if (!this._wasLocalized) {
        // Don't update UI state until we will localize the toolbar.
        return;
      }

      let selectScaleOption = (value, scale) => {
        let customScale = Math.round(scale * 10000) / 100;
        this.l10n.get('page_scale_percent', { scale: customScale, },
                      '{{scale}}%').then((msg) => {
          let options = items.scaleSelect.options;
          let predefinedValueFound = false;
          for (let i = 0, ii = options.length; i < ii; i++) {
            let option = options[i];
            if (option.value !== value) {
              option.selected = false;
              continue;
            }
            option.selected = true;
            predefinedValueFound = true;
          }
          if (!predefinedValueFound) {
            items.customScaleOption.textContent = msg;
            items.customScaleOption.selected = true;
          }
        });
      };

      var pageNumber = this.pageNumber;
      var scaleValue = (this.pageScaleValue || this.pageScale).toString();
      var scale = this.pageScale;

      var items = this.items;
      var pagesCount = this.pagesCount;

      if (resetNumPages) {
        if (this.hasPageLabels) {
          items.pageNumber.type = 'text';
        } else {
          items.pageNumber.type = 'number';
          this.l10n.get('of_pages', { pagesCount, }, 'of {{pagesCount}}').
              then((msg) => {
            items.numPages.textContent = msg;
          });
        }
        items.pageNumber.max = pagesCount;
      }

      if (this.hasPageLabels) {
        items.pageNumber.value = this.pageLabel;
        this.l10n.get('page_of_pages', { pageNumber, pagesCount, },
                      '({{pageNumber}} of {{pagesCount}})').
            then((msg) => {
          items.numPages.textContent = msg;
        });
      } else {
        items.pageNumber.value = pageNumber;
      }

      items.previous.disabled = (pageNumber <= 1);
      items.next.disabled = (pageNumber >= pagesCount);

      items.zoomOut.disabled = (scale <= MIN_SCALE);
      items.zoomIn.disabled = (scale >= MAX_SCALE);

      selectScaleOption(scaleValue, scale);
    },

    updateLoadingIndicatorState:
        function Toolbar_updateLoadingIndicatorState(loading) {
      var pageNumberInput = this.items.pageNumber;

      if (loading) {
        pageNumberInput.classList.add(PAGE_NUMBER_LOADING_INDICATOR);
      } else {
        pageNumberInput.classList.remove(PAGE_NUMBER_LOADING_INDICATOR);
      }
    },

    _adjustScaleWidth: function Toolbar_adjustScaleWidth() {
      var container = this.items.scaleSelectContainer;
      var select = this.items.scaleSelect;
      animationStarted.then(function() {
        // Adjust the width of the zoom box to fit the content.
        // Note: If the window is narrow enough that the zoom box is not
        //       visible, we temporarily show it to be able to adjust its width.
        if (container.clientWidth === 0) {
          container.setAttribute('style', 'display: inherit;');
        }
        if (container.clientWidth > 0) {
          select.setAttribute('style', 'min-width: inherit;');
          var width = select.clientWidth + SCALE_SELECT_CONTAINER_PADDING;
          select.setAttribute('style', 'min-width: ' +
                                      (width + SCALE_SELECT_PADDING) + 'px;');
          container.setAttribute('style', 'min-width: ' + width + 'px; ' +
                                          'max-width: ' + width + 'px;');
        }
      });
    },
  };

  return Toolbar;
})();

export {
  Toolbar,
};
